(a) Field of the Invention
The present invention relates to a controlling method and system for a damper clutch of an automatic transmission. More particularly, the present invention relates to a controlling method and system for a damper clutch that control a damper clutch release condition according to a direct connection status of a damper clutch.
(b) Description of the Related Art
A typical automatic transmission uses a torque converter with low efficiency, and thus, compared to a manual transmission, it has a critical drawback in fuel consumption. To overcome this drawback, a damper clutch that directly connects and releases a pump axis of a torque converter to a turbine has been provided. This prevents deterioration of fuel consumption due to power loss generated by a rotation-speed difference between the pump axis and the turbine axis above a predetermined vehicle speed.
The release condition of the damper clutch is determined by conditions such as an oil temperature, engine speed, vehicle speed, turbine speed, and variation of a throttle opening. Particularly, the variation of a throttle opening relates to a shock of the damper clutch. However, in a conventional control method of the damper clutch, the engagement or release has been determined by a variation of a throttle opening regardless of the direct connection status (i.e. a direct connection status in a power-on state or a direct connection status in a power-off state). Consequently, the damper clutch might not be controlled according to various running states.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.